Jar 1 contains 10 red marbles. Jar 2 contains 10 blue marbles. You take 3 red marbles from Jar 1 and mix them into Jar 2. Then you take 3 random marbles from Jar 2 and put them back into Jar 1. Is there now more blue in Jar 1 than red in Jar 2, or vice versa, or are they equal?
They are equal.
Both jars begin and end with 10 total marbles. Any red marbles missing from Jar 1 must now reside in Jar 2. Because Jar 1 ends up with 10 marbles total, every missing red marble was replaced by a blue marble from Jar 2. Thus, the count of blue marbles in Jar 1 equals the count of red marbles in Jar 2.
About this riddle
Logic riddles give you a few facts and ask what must be true. List what you know, cross out what cannot be, and see what is left.
Difficulty: Medium. More like this: Logic riddles with answers or try Einstein's Logic Grid for a different kind of puzzle.
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